Beabing solutions



E. H. RICHARDS ET AL Y MANUFACTURE OF -NITROG-rENOUSv FERTILIZERS AND THE UTILIZATION DF NITROGEN BEARING SOLUTIONS *nominal Filed Aug. 12..1921

Y r e .Y

` Aug'. 30, 1932.

Reissued Aug. 30, 1.932 i .uble nitrogenous compounds be brought into transformed into insoluble derivatives which,

' ent kinds ofthe said fermentabl'e substances of' this material will render/insoluble and account.

' nitrogen becomes available and easily assimilkind of material is strictly limited. For exvwRe. 18,581

ENT-OFFICE ERIC HANNAFORD RICHARDS, OF HAREIEINDIEIN'.l AND HENRY BROUGHAM H-UTCHINSON, 0F EPSON, ENGLAND, ASSIGNORS T0 ADCO LIMITED, 0F HARPENDEN, ENGLAND. A.

BRITISH GOIIIANYY v MANUFACTURE OI-FNITROGENOUS FERTILIZERS AND THE UTILIZATION OF NITROGEN- BEARING SOLUTIONS Original No. 1,471,979, dated October 23,v 1923, Serial No. 491,774, med August 12, 1921. Application for reissue illed February 1'0, 1931. Serial No. 514,879.

will retain from 7 to 10 parts of soluble' nitrogen, equivalent to 35 to 50 parts of the soluble nitrogen com ound such, for instance, as ammonium sulp ate. As stated above, since under appropriate conditions practical- This invention is for improvements in and relating to the production of nitrogenous fertilizers and the utilization of solutions of soluble nitrogen.

The invention aims at providing a simple. process for the production of nitrogenous fertilizers from solutions of nitrogenous'A compounds. Such solutions may beartificially prepared for the purpose, or suitable nitrogenous waste liquids from industrial and other sources may be employed. vVarious attempts have been made to utilize 'these attenuated solutions, but no satisfactory method has hitherto been devised for the economical recovery of their nitrogen. This invention, therefore, also serves to afford means for turning such Waste liquids to profitable moved from the solution and recovered in organic combination by treatment of 1000 parts of wheat straw With about 7 to 10 parts of soluble nitrogen, a',fertilize r Whose nitrogen is'available to and readily assimilable by plants is produced with a maximum of economy.

A characteristic feature ofthe process of this invention resides in the utilization, as food for group of organisms which require nitrogen for the elaboration of their own bodies, of the more easily digestible portions The present invention is based upon studies which demonstrate that under appropriate conditions definite reactions may be brought about between suitable carbohydratecontaining materials and nitrogenous solu tions, whereby practically the Whole of the nitrogen may be removed from the solution and recovered in organic combination. The nitrogenous productsso obtained are insoluble in Water, but in presence of soil the bracken,ror other suitable carbonaceous material, hereinafterdeslgnated carbohydrate- `conta1n1ng materlal, smce starch, sugar or ment of the organisms in question. These organisms are highly aerobic and, under proper aerobic conditions, in`presence of nitrogeneous solutions, such as, for example,

nitrogen from the solution and carbon from the more digestible cppstituents of the carbohydrate-containing matter and effect the comblnation of these elements with production of insoluble derivatives in their own cellstructure or excretions. normally normally ound in substances such as straw, and an organic nutrient inoculated with these organisms may be conveniently ,designated as fermentable carbohydrate-containing material. satisfactorilyr 'in forming insoluble nitrogen compounds, however, a certain condition of able by plants.

Our investigations demonstrate that if solcontact with a substance containing fermentable carbohydrate-containing compounds, such, for instance, as straw, and fermentation be allowed to proceed under suitable conditions, the soluble nitrogenous compound is however, are retained by the lcarbonaceous material, now partially fermented. Differare distinguished one from another in respect to their capacity to form and retain the insoluble nitrogen compounds, This property o f retention ma be described as loading with the insolu le derivatives in question, 'and the retentive capacity of each brought about, that is to say, va plentiful growth of these organisms must have occurred. Fermentable material in which this condition has been established 'is hereafter referred to as activatedtin this specification ample, in the case of-wheat straw, 1000 parts and claims. The action of these organisms of vegetable matter such as straw, dead leaves, l

cellulose is a necessary food for the develop- These organisms are resent in soil, and are therefore 55 ly the lwhole of the nitrogen may be resolutions of ammoniacalnitrogen, they take Before such material can function development of the organisms must be has definite limits, as stated above, and, given bility in water.

of a proper reaction and effective aerobic conditions.

The-terms soluble and insoluble are employed in this specification and claims as denoting respectively solubility and insolu- According to the pres'entinvention, a process for the production of a nitrogenous ferti= lizer andthe utilization of solutions of soluble nitrogenous compounds comprises treat-` ing a fermentable carbohydrate containing material with a nitrogen-bearing solution under aerobic conditions.

Thevactivated material may be 'obtained by maintaining a fermentable carbohydrate-containing substance in contact under aerobic conditions with a solution of a nitrogenous compound `until the organisms vare vactively developed.

Obviously, if the organic material avail-` able be sterile in respect to these` nitrogen-fixing organisms, it may be inoculated with them and activated by aerobic contact with a nitrogenous solution which hasv already been treated with activated carbohydrate-containing matter. l

Advantageously, the carbohydrate-containing material is maintained in contact with the solution until it is fully loaded with insoluble nitrogenderivatives formedl from the soluble nitrogen and/ or until the greater proportion of soluble nitrogen in the solution has been`transformed into the insoluble state.

Any suitablenitrogenous product may be used to furnish the source of soluble nitrogen. For example, there may be employeda.

solution of cyanamide or of an ammonium Salt, forlnstance, ammomum carbonate, or

` ammonium sulphate, "or the residual liquors lfrom ammonia recovery plants from which `liquors ammonium sulphate hasalreadybeen recovered, may be used. Alternatively, the soluble nitrogenous compound may be derived from sewage,l or the easily available .organic nitrogen in abattoir refuse, and the present `1nvent1on therefore provides a means ofv recovering the nitrogen from this vsource in aconvenient available form. The'nitrates and nitrites of the alkali metals have not been Y found suitable for the purpcse's of our invention, andthe term soluble nitrogen as used in this specification and in the claims'V is to be understood as not including these salts.

Nltrogen bearing solutions so treated, even 'ifthey be derived from wasteliquids such \as sewage of normal strength, are not putrescible on incubation, and `are,therefore,.un

. objectionable except perhaps in respect totheir more or less brown colour` due t9 the of the operative organisms. Moreover, working with too concentrated solutions results in waste of a substantial quantity of nitrogen, which is lost instead of passing into organic combination. v

If the fermentation becomes too` acid, the proper biological action is completely inhibited; the reaction should therefore be-neutral or slightly alkaline. In certain cases, itI may beadvisable to add a lcertain proportion of a neutralizing agent, for example, calcium carbonate, either alone or in conjunction with i a soluble phosphate, to the nitrogenous solution. In carrying the invention into eect in one 90 Way, a solution of ammonium carbonate of a concentration equivalent to 10 parts of soluble nitrogen per 100,000 parts of solution is exposed to contact with activated 'straw by causing the solution to percolate through the straw, with free access of air, at the rate of about 250 gallons per cubic yard of straw per 24 hours, this representing the optimum vrate of delivery for a solution of this concentration and for properly activated straw. The straw, if not alread activated, may be brought into this condition for this process by maintaining itin contact, with free access of air, with the solution of ammonium carbonate, for a suticient period of time, for example, for notless than hours. That an appropriate time of contact is one of the conditions for ecoiomical utilization'of the dis# solved nitrogen, in order that the carbohydrate-containing material shall be fully load- 110 ed, has already been pointed out, and when methodssuch as percolationare employed the simplest means of fulfilling this condition 4is by 'regulation of the rate of flow of the nitrogenous solution. 115

As regards the solution, the process ispreferably carried to that point at which the contacting liquid does not contain more ythan Aabout 10 per cent. of the nitrogen originally present in it, resulting inthe transformation 120 When the lowest layer of straw is fully saturated with insoluble nitrogen, this layer is removed and the second l'ayer is allowedto drop by withdrawing the supporting members D. The r'st layer is similarly transferred and is replaced at the top by fresh activated straw. As the end of any cycle, the lowest layer of straw is'the substantially `fully loaded material, the second andrst layers are those of straw in an earlier and still earlier stage of treatment respectively. Y.

It will usually be found that when percolation is adopted, the rate of delivery of tne solution is, other things being equal, determined by the concentration, and as a general guide it may be said that the limit of concentration for this mode of operation is represented by 100 parts of soluble nitrogen per 100,000 parts of solution. Solutions of lower concentration than this are, however, tobe preferred as a rule for economical reasons.

Throughout the period of treatment aerobic conditions and a neutral or slightly alkaline reaction must bemaintained.

The solution in contact with the straw may also be treated with air under pressure, or the straw and solution may be agitated together by mechanical mea-ns.

The material containing the insolublenitrogen compounds is directly available as manuret may, however, be' stored, underA cover if desired, `for a suitable length of time, say, three months, during which period it lsuifers loss in d matter,'up to, for instance, 40' per cent-of t e original weight of the untreated drate-containing material to 2 to 21/2 per cent. l

The physical condition of the final product resembles that of well-rotted stable manure.

The following is an example of a convenient mode of procedure for the production of a fertilizer when the plant xrfethod is not desired and where the successive processes of activation, loading, and rotting are combined m one operation:

. 1 ton of dry straw is built up into a heap, and as the heap is made up there is mixed in 1 cwt. -of ammonium sulphate and -1 cwt. of lfine chalk or limestone. Water is then added cautiously so that none runs away until about 4 tons have been absorbed by the straw. Alternatively, the straw and the chalk may be wetted first and the ammonium sulphate applied subsequently. The mass is then left for three months. is turned over a month from the start.

Advantageously, the heap The figures given represent a mtrogenconcentration in the solution 4of 0.25 per cent. at the start. This corresponds to 10 parts of nitrogen per 1000 quarts of dry straw. Of this nitrogen, a small proportion is lost in the three months,l the remainder being .transformed into organic combination. Since the straw has a retentive capacity of 7 to 10 parts of soluble nitrogen per 1000 parts of straw, as previouslyexplained, a substantially loaded product is obtained. An initial nitrogen concentration of 0.5 per cent. gives an equally good manure, but as this corresponds to 20 parts of solublenit'rogen per 1000 parts of straw or twice 'as much nitrogen as can be retained, a high percentage of nitrogen is lost. This is an illustration of the economic advantage of not using nitrogenous solutions of too high concentration, that isto say,'solut1ons containing a signilicant excess of nitrogen.

We claim:

1. The process for producing a fertilizer in the form of an hydrated organic agglomcrate containing available nitrogen in insoluble organic c0mbination,which comprises contacting activated carbohydrate-contaming material under aerobic conditions forv an e xtended time, with a solution of a soluble nitrogenous compound other than alkali metal nitrates or nitrites, in the proportion of 7 to 1 0 parts of nitrogen to^1,000 parts of dry carbohydrate-containing material.`

2. The process for producing a fertilizer in the form of an hydrated organic agglomerato containing available nitrogen.v in insoluble organic combination, which comprises contacting l activated carbohydrate-containing material .under aerobic conditions for an extended time, with a solution of ammoniacal nitrogen inthe proportion of 7 to'10 parts of nitrogen to 1,000 parts of dry carbohydratecontaining material. carbohydrate-containing material, the nitro- 1.

3.'The process for producing a fertilizer "in the form of an hydrated organic agglomerate containing available nitrogen in insoluble organic combmation, which comprises contacting activated carbohydrate-containing material under aerobic conditions for an extended time, with a solution of ammoniacal nitrogen in the proportion of 7 vto 1() parts of nitrogen to 1,000parts of dry carbohydrate-containing material and maintaining a substantially neutral to slightly alkaline reaction with an antacid.

4. The process forproducing a fertilizer in the formof an hydrated organic agglomerate containing available nitrogen in ins'ol-l uble organic combination, which comprises contacting activated straw lunder aerobic conditions for an extended time, with a solution of a soluble nitrogenous compound other than alkali metal'nltrates or nitrites, in the proportion ofv7 to l0 parts of nitrogen, to 1,000 parts of dry straw.

5,. The lprocess for producing a fertilizer in the form of an hydrated organic agglomerate containing available nitrogen in insoluble organic combinatlon, which comprlses contacting activated straw under aerobic conditions for an extended time, with a solution of ammonacal nitrogen in the proportion of 7 to 10 of dry straw. y

6. The process for producing Va fertilizer in the form of an hydrated organic agglomerate containing available nitrogen in insoluble organic combination, which comprises contacting activated straw 'under aerobic conditions for an extended time, with a solution of ammoniaeal nitrogen in the proportion of 7 to 10 parts of nitrogen 'to 1,000 parts of dry straw and maintaining substantia1lyneutral to slightly alkaline reaction with an antacid. ERIC HANNAFORD RICHARDS.

HENRY BROUGHAM H UTCHINSON.

parts of nitrogen to 1,000 parts g 

